Steering-wheel brake mechanism for motor vehicles



Oct. 13,1925- F. PORSCHE STEERING WHEEL BRAKE MECHANISM FOR MOTOh VEHICLES- Filed March 14, 1925 Patented Oct. 13, 1925.

UNITED STATES. l'P'll-IN' OFFCE'.

FERDINAND PORSCHE, O'F STUTTGART-UNTERTURKHEIM, GERMANY, ASSGNOR TO THE FIRM. DAIMLER-MOTOBEN-GESELLSCHAET, F STUTTGART#UNTERTURKHEIII,

GERMANY.

STEERING-W'HEEL BRKE MECHANISM FOR MOTOR VEHICLES.

Application filed March 14, 1925. Serial No. 15.691.

i To aZZ 'Lv/uom t may concern.'

Be it known that I, FERDINAND PORSCHE,

"a'citizen of the Republic of Czechoslovakia,

' residing at Stuttgart-Unterturkheim, Wurt- `l temberg, Germany, lVlercedesstrasse have invented certain new and useful Im-` provements in Steering-Wheel Brake Mech anism for Motor Vehicles, of which the -following is a specication. 1Q The invention relates to brake mechanism,

and is intended for application primarily to the steering roadwheels of motor vehicles, in which the .transmission of the braking ymoment or braking force to the brake is eected through a brake shaft lmounted in the wheel axle to a thrust rod displac'eably mounted in the hollow steering swivel journal.

The invention differs from the known the brake shaft is mounted in a longitudinal bore in the wheel axle outside the bearing for the steering swivel journal, and acts on f the thrust (rod through a cam arranged outside the bearing for the steering swivel journal; and further in that the axes of the thrust rod and brake shaft are situated in the same plane. .c

In a steering-wheel brake according to the invention, the cam transmitting the braking effort from the brake shaft to` the thrust rod has laterally projecting parallel walls forming a guide, between which engages the bent end of the thrust rod.

355% Further, according tov the invention, the brake shaft rotatably mounted in the front axle is packed or engaged against thel cover plate of the -brake by a spring-loaded ball socket.

invention -att'ords several advantages.

Owing to the brake shaft and thrust rod ing of the brake shaft inside the body of the axle itself presents the advantage that the otherwise necessary members for Supl` porting the brake shaft are dispensed wit steering 4wheel brakes of this type in that,

A steering-wheel brake according to thel braking moment or effort from the brake` complicated devices. Moreover, the arrangthe manufacture `being consequently simplilied and the cost of production reduced.

On the 4other hand, owing to the brake shaft lying outside the bearing of the steering swivel journal, the interior of the drinn can be eectually closed infa'ls'iniplemanner. No parts capable 'of rendering th'efelosing Aof t-he vdrum dil'licult and necessitating the adoption of troublesome measures are situd ated i'n the middle of the drum.l closure that is not' liable to be impaired by A tight the presence of complicated devices is, however, an esesntial condition for efficient braking and the prevention of premature wear of individual parts through the penetration'of dust.

lIn the drawing, a typical embodiment of the invention is illustratedv by three figures Figure l shows a vertical section through the brake drum, steering swivel and adjacent parts. Figure 2 shows a horizontal section along the line A-A of Figure l'. Figure 3 shows a side elvation of the brake mechanism in partial section.

The hub 2 of the wheel (not shown) is mounted on the journal l of the steering swivel in the usual manner, and on this hub is attached the brake drum The brake consists, for example, as lshown in Figure 3,

of the two brake cheeks 4t, which are retained by pivot pins 5. Between the two brake cheeks is arranged a cani 6, which serves in known manner to force the brake cheeks l apart and thus press them against the brake drum 3. In this movement of the cam, the springs 7 are placed under tension, and when the cam has been returned toits formery position, the pull of the springs draws the. brake cheeks away from the drum 3.

The device provided, according to the invention, for acting on the brake, is constituted as follows z- The cross shaft 8, which is mounted in a bore 10 in the road wheel axle 9, carries on its one end for example a lever 11, to which is attached arod (not shown) leading tol the hand lever. On the other end of the cross shaft is situated a cam 12, which'turns with said shaft. Against the cam 12 bears .a small rod 18, which .passes through-the for the rod 13 is preferably admitted between the two bearing points, thusproducing good and reliable lubrication. -On the side away from the cam, the rod 13 is connected, by a link 17, with the lever 18 which turns the cam 6 to press the brake cheeks aginst the brake drum.

As can be seen from Figurel, the cam 12 is provided with projecting'lateral lugs 19, which engage between them the small rod 13 so that the latter cannot turn.

l Asis principally shown by Figure 3 the laxial centre :cof the cross shaft 8 and of the ca m 12 mounted thereon, and also the axis` :c1 of the rod 13 and the centre m2 of the pivotal point 17, aresituated on the pivotal axis y'-y of the steering swivel. As' the result of such arrangement of the parts, these latter are not moved out of their original position-When the wheel is turned in steering, and consequently the usual inter,- mediate links are dispensed with. Moreover, the parts themselves can be conveni- -ently arranged and simplilie-dhso that a further considerable advantagein point of reliability in operation 1s obtained.

The invention also provides a simple method of closure for the gap- 191 in the guard plate 20. A ball socket 21 is mounted in a nonrotatable manner on the cross shaft 8, and `bears against a correspondingly shaped member 22, attached to the guard plate, undei` the pressure of a spring 23. To enable the road wheel to swing in relation to the fixedly mounted cross shaft 8K, a suitable transverse slot 24, closely covered by the ball socket, is provided in the guard plate. The vposition takenI up by the guard' plate in relation to the ball socket during the steering movement of thewvheel is indicated by' dotted lines in Figure 2.

1. In combination with an axle of an automobile having a hollow portion and having a steering wheel turnably connected thereto by a journal member, a-brakedrum associated with said steering wheel, brake'members pivotally connected to said steering wheel and located within said brake drum,

a cam turnably connected to said' steering wheel and adapted to force the brake members associated with said steering wheel out- Wardly against the inner surface of the said brake drum,a rod slidably" located within said journal member and connected to 'the said cam, a b'rake-actuatingshaft located within the saidl hollow portion of said axle and having its ends projecting lbeyond the .said hollow portion, an actuatingmember connected to that end 'of said shaft which is furthest from said steering wheel, the end of the said brake-actuating shaft which is adjacent saidwheel havingacam adapted to co-operate with the said slidable rod to actuate-the first mentionedcam, a spring associated with said slidable rod and adaptthe hollow portion of said axle,'brake'inech anism associated with said wheel, theb'rake mechanism for said Wheel being connected with theprojecting end of said brake shaft adjacent said wheel, operating means con'-H nected to the 'other projecting portion 'of said brake-actuating'shaft, a perforated .cover plate for said brake mechanism ada 'tf ed to enclose the same, theend of said vbra 'ef i project? cover actuating shaft adjacent said wheel ing through the perforation 1n sai plate, the said adjacent end of said brakeactuating shaft havinga non-revolubleball l socket connected thereto, said ball socket being forced against va correspondingly i shaped member connectedto said cover platev b y means of an lintermediate spring. A In testimony whereof. I aiiix my signature.

FERDINAND. PORSCHE.` 

